7/24/2019 scribd doc 1.docx

http://slidepdf.com/reader/full/scribd-doc-1docx 1/18

For a broader coverage related to this topic, see  Nature.

For the biology term, see Environment (biophysical). For other uses, see Environment.

"Natural force" redirects here. It is not to be confused with Natural Force.

and management policies have been developed to preserve the natural characteristics of

!opetoun Falls, ustralia while allowing ample access for visitors.

#achalpsee in the $wiss lps% &ountainous areas in $wit'erland are summer farm pasture.*

satellite image of the $ahara desert+ the worlds largest hot desert and third-largest desert afterntarctica and the rctic.

he natural environment encompasses all living and non-living things occurring naturally on

Earth or some region thereof. It is an environment that encompasses the interaction of all living

species. /limate, weather, and natural resources that affect human survival and economicactivity. 0* he concept of the natural environment  can be distinguished by components%

• /omplete ecological units that function as natural systems without massive civili'ed

human intervention, including all vegetation, microorganisms, soil, roc1s, atmosphere,

and natural phenomena that occur within their boundaries

• 2niversal natural resources and physical phenomena that lac1 clear-cut boundaries, such

as air, water, and climate, as well as energy, radiation, electric charge, and magnetism,

not originating from civili'ed human activity

7/24/2019 scribd doc 1.docx

http://slidepdf.com/reader/full/scribd-doc-1docx 2/18

In contrast to the natural environment is the built environment. In such areas where man has

fundamentally transformed landscapes such as urban settings and agricultural land conversion,

the natural environment is greatly modified and diminished, with a much more simplified humanenvironment largely replacing it. Even events which seem less e3treme such as hydroelectric

dam construction, or photovoltaic system construction in the desert, the natural environment is

substantially altered.

It is difficult to find absolutely natural  environments, and it is common that the naturalnessvaries in a continuum, from ideally 445 natural in one e3treme to 45 natural in the other. &ore

 precisely, we can consider the different aspects or components of an environment, and see that

their degree of naturalness is not uniform.6* If, for instance, we ta1e an agricultural field, andconsider the mineralogic composition and the structure of its soil, we will find that whereas the

first is 7uite similar to that of an undisturbed forest soil, the structure is 7uite different.

 Natural environment  is often used as a synonym for habitat. For instance, when we say that the

natural environment of giraffes is the savanna.

Contents

• /omposition

• 0 8eological activity

• 6 9ater on Earth 

o 6. :ceans

o 6.0 ;ivers 

6.0. $treams

o 6.6 a1es 

6.6. <onds

• = tmosphere, climate and weather  

o =. tmospheric layers 

=.. <rincipal layers

=..0 Effects of global warming

o =.0 /limate

7/24/2019 scribd doc 1.docx

http://slidepdf.com/reader/full/scribd-doc-1docx 3/18

o =.6 9eather 

• > ife

• ? Ecosystems

• @ #iomes

• A #iogeochemical cycles

• B 9ilderness

• 4 /hallenges

• /riticism

• 0 $ee also

• 6 ;eferences

• = Further reading

• > E3ternal lin1s

Composition

he Earths layered structure. () inner core+ (0) outer core+ (6) lower mantle+ (=) upper mantle+(>) lithosphere+ (?) crust

7/24/2019 scribd doc 1.docx

http://slidepdf.com/reader/full/scribd-doc-1docx 4/18

 volcanic fissure and lava channel.

&ain article% Earth science

Earth science generally recogni'es = spheres, the lithosphere, the hydrosphere, the atmosphere,and the biosphere=* as correspondent to roc1s, water , air , and life. $ome scientists include, as part

of the spheres of the Earth, the cryosphere (corresponding to ice) as a distinct portion of the

hydrosphere, as well as the  pedosphere (corresponding to soil) as an active and intermi3edsphere. Earth science (also 1nown as geoscience, the geosciences or the Earth $ciences), is an

all-embracing term for the sciences related to the planet Earth.

>*

 here are four maCor disciplines in earth sciences, namely geography, geology, geophysics and geodesy. hese maCor disciplines

use physics, chemistry,  biology, chronology and mathematics to build a 7ualitative and7uantitative understanding of the principal areas or   spheres of the Earth.

Geological activity

&ain article% 8eology

he Earths crust, or lithosphere, is the outermost solid surface of the planet and is chemicallyand mechanically different from underlying mantle. It has been generated greatly by igneous 

 processes in which magma cools and solidifies to form solid roc1. #eneath the lithosphere liesthe mantle which is heated by the decay of  radioactive elements. he mantle though solid is in astate of rheic convection. his convection process causes the lithospheric plates to move, albeit

slowly. he resulting process is 1nown as plate tectonics. Dolcanoes result primarily from the

melting of subducted crust material or of rising mantle at mid-ocean ridges and mantle plumes.

Water on Earth

/oral reefs have significant marine biodiversity.

7/24/2019 scribd doc 1.docx

http://slidepdf.com/reader/full/scribd-doc-1docx 5/18

Oceans

&ain article% :cean

n ocean is a maCor body of saline water , and a component of the hydrosphere. ppro3imately

@5 of the Earths surface (an area of some 6?0 million s7uare 1ilometers) is covered by ocean,a continuous body of water  that is customarily divided into several principal oceans and smaller

seas. &ore than half of this area is over 6,444 meters (B,A44 ft) deep. verage oceanic salinity isaround 6> parts per thousand (ppt) (6.>5), and nearly all seawater has a salinity in the range of

64 to 6A ppt. hough generally recogni'ed as several separate oceans, these waters comprise

one global, interconnected body of salt water often referred to as the 9orld :cean or globalocean.?*@* his concept of a global ocean as a continuous body of water with relatively free

interchange among its parts is of fundamental importance to oceanography.A* he maCor oceanic

divisions are defined in part by the continents, various archipelagos, and other criteria% thesedivisions are (in descending order of si'e) the <acific :cean, the tlantic :cean, the Indian

:cean, the $outhern :cean and the rctic :cean.

Rivers

he /olumbia ;iver , along the border of the 2.$. states of :regon and 9ashington.

roc1y stream in the 2.$. state of !awaii&ain article% ;iver 

river is a natural watercourse,B* usually freshwater , flowing toward an ocean, a la1e, a sea oranother river. In a few cases, a river simply flows into the ground and dries up completely before

reaching another body of water. $mall rivers may also be termed by several other names,

including stream, cree1 and broo1. In the 2nited $tates a river is generally classified as awatercourse more than ?4 feet (A metres) wide. he water in a river is usually in a channel,

7/24/2019 scribd doc 1.docx

http://slidepdf.com/reader/full/scribd-doc-1docx 6/18

made up of a stream bed between  ban1s. In larger rivers there is also a wider floodplain shaped

 by waters over-topping the channel. Flood plains may be very wide in relation to the si'e of the

river channel. ;ivers are a part of the hydrological cycle. 9ater within a river is generallycollected from precipitation through surface runoff , groundwater  recharge, springs, and the

release of water stored in glaciers and snowpac1s.

Streams

&ain article% $tream

stream is a flowing body of water  with a current, confined within a bed and stream ban1s.$treams play an important corridor  role in connecting fragmented habitats and thus in conserving

 biodiversity. he study of streams and waterways in general is 1nown as surface hydrology.4* 

ypes of streams include cree1s, tributaries, which do not reach an ocean and connect withanother stream or river, broo1s, which are typically small streams and sometimes sourced from a

spring or seep and tidal inlets

Lakes

he car a1e is a la1e of glacial origin in the province of Neu7un, rgentina.

 swamp area in Everglades National <ar1 , Florida, 2$.&ain article% a1e

la1e (from atin lacus) is a terrain feature, a body of water that is locali'ed to the bottom of

 basin. body of water is considered a la1e when it is inland, is not part of an ocean, is larger and

deeper than a pond, and is fed by a river.*0*

7/24/2019 scribd doc 1.docx

http://slidepdf.com/reader/full/scribd-doc-1docx 7/18

 Natural la1es on Earth are generally found in mountainous areas, rift 'ones, and areas with

ongoing or recent glaciation. :ther la1es are found in endorheic basins or along the courses of

mature rivers. In some parts of the world, there are many la1es because of chaotic drainage patterns left over from the last Ice ge. ll la1es are temporary over geologic time scales, as they

will slowly fill in with sediments or spill out of the basin containing them.

Ponds

&ain article% <ond

pond is a body of standing water , either natural or man-made, that is usually smaller than ala1e. wide variety of man-made bodies of water are classified as ponds, including water

gardens designed for aesthetic ornamentation, fish ponds designed for commercial fish breeding,

and solar ponds designed to store thermal energy. <onds and la1es are distinguished from streamsvia current speed. 9hile currents in streams are easily observed, ponds and la1es possess

thermally driven micro-currents and moderate wind driven currents. hese features distinguish a

 pond from many other a7uatic terrain features, such as stream pools and tide pools.

Atmosphere, climate and eather

tmospheric gases scatter blue light more than other wavelengths, creating a blue halo when

seen from space.

view of Earths troposphere from an airplane.

7/24/2019 scribd doc 1.docx

http://slidepdf.com/reader/full/scribd-doc-1docx 8/18

ightning is an atmospheric discharge of electricity accompanied by thunder , which typicallyoccurs during thunderstorms, and sometimes during volcanic eruptions or  dust storms.6*

he atmosphere of the Earth serves as a 1ey factor in sustaining the planetary ecosystem. he

thin layer of gases that envelops the Earth is held in place by the planets gravity. Gry air  consists

of @A5 nitrogen, 05 o3ygen, 5 argon and other  inert gases, such as carbon dio3ide. heremaining gases are often referred to as trace gases,=* among which are the greenhouse gases 

such as water vapor, carbon dio3ide, methane, nitrous o3ide, and o'one. Filtered air includestrace amounts of many other chemical compounds. ir also contains a variable amount of  watervapor  and suspensions of water droplets and ice crystals seen as clouds. &any natural substances

may be present in tiny amounts in an unfiltered air sample, including dust,  pollen and spores, sea

spray, volcanic ash, and meteoroids. Darious industrial pollutants also may be present, such aschlorine (elementary or in compounds), fluorine compounds, elemental mercury, and sulphur  

compounds such as sulphur dio3ide $:0*.

he o'one layer  of the Earths atmosphere plays an important role in depleting the amount of

ultraviolet (2D) radiation that reaches the surface. s GN is readily damaged by 2D light, thisserves to protect life at the surface. he atmosphere also retains heat during the night, thereby

reducing the daily temperature e3tremes.

Atmospheric layers

&ain article% Earths atmosphere

Principal layers

Earths atmosphere can be divided into five main layers. hese layers are mainly determined by

whether temperature increases or decreases with altitude. From highest to lowest, these layers

are%

• E3osphere% he outermost layer of Earths atmosphere e3tends from the e3obase upward,

mainly composed of hydrogen and helium.

• hermosphere% he top of the thermosphere is the bottom of the e3osphere, called the

e3obase. Its height varies with solar activity and ranges from about 6>4HA44 1m (004H 

>44 mi+ ,>4,444H0,?04,444 ft). he International $pace $tation orbits in this layer, between 604 and 6A4 1m (044 and 0=4 mi).

7/24/2019 scribd doc 1.docx

http://slidepdf.com/reader/full/scribd-doc-1docx 9/18

• &esosphere% he mesosphere e3tends from the stratopause to A4HA> 1m (>4H>6 mi+

0?0,444H0@B,444 ft). It is the layer where most meteors burn up upon entering the

atmosphere.

• $tratosphere% he stratosphere e3tends from the tropopause to about > 1m (60 mi+

?@,444 ft). he stratopause, which is the boundary between the stratosphere andmesosphere, typically is at >4 to >> 1m (6 to 6= mi+ ?=,444 to A4,444 ft).

• roposphere% he troposphere begins at the surface and e3tends to between @ 1m

(06,444 ft) at the poles and @ 1m (>?,444 ft) at the e7uator, with some variation due toweather. he troposphere is mostly heated by transfer of energy from the surface, so on

average the lowest part of the troposphere is warmest and temperature decreases with

altitude. he tropopause is the boundary between the troposphere and stratosphere.

:ther layers

9ithin the five principal layers determined by temperature are several layers determined by other  properties.

• he o'one layer  is contained within the stratosphere. It is mainly located in the lower

 portion of the stratosphere from about >H6> 1m (B.6H0.@ mi+ =B,444H>,444 ft),

though the thic1ness varies seasonally and geographically. bout B45 of the o'one in our atmosphere is contained in the stratosphere.

• he ionosphere, the part of the atmosphere that is ioni'ed by solar radiation, stretches

from >4 to ,444 1m (6 to ?0 mi+ ?4,444 to 6,0A4,444 ft) and typically overlaps both

the e3osphere and the thermosphere. It forms the inner edge of the magnetosphere.

• he homosphere and heterosphere% he homosphere includes the troposphere,

stratosphere, and mesosphere. he upper part of the heterosphere is composed almost

completely of hydrogen, the lightest element.

• he planetary boundary layer  is the part of the troposphere that is nearest the Earths

surface and is directly affected by it, mainly through turbulent diffusion.

E!!ects o! glo"al arming

he ;etreat of glaciers since A>4 of letsch 8lacier  in the $wiss lps (situation in B@B, BB

and 0440), due to global warming.

7/24/2019 scribd doc 1.docx

http://slidepdf.com/reader/full/scribd-doc-1docx 10/18

&ain article% Effects of global warming

he potential dangers of global warming are being increasingly studied by a wide global

consortium of scientists. hese scientists are increasingly concerned about the potential long-term effects of global warming on our natural environment and on the planet. :f particular

concern is how climate change and global warming caused by anthropogenic, or human-madereleases of greenhouse gases, most notably carbon dio3ide, can act interactively, and have

adverse effects upon the planet, its natural environment and humans e3istence. It is clear the planet is warming, and warming rapidly. he most recent report from the Intergovernmental

<anel on /limate /hange (the group of the leading climate scientists in the world) concluded that

the earth will warm anywhere from 0.@ to almost degrees Fahrenheit between BB4 and 044.>* Efforts have been increasingly focused on the mitigation of greenhouse gases that are causing

climatic changes, on developing adaptative strategies to global warming, to assist humans, other

animal, and plant species, ecosystems, regions and nations in adCusting to the effects of globalwarming. $ome e3amples of recent collaboration to address climate change and global warming

include%

nother view of the letsch 8lacier  in the $wiss lps and because of  global warming it has been

decreasing

• he 2nited Nations Framewor1 /onvention reaty and convention on /limate /hange,

to stabili'e greenhouse gas concentrations in the atmosphere at a level that would preventdangerous anthropogenic interference with the climate system.?*

• he yoto <rotocol, which is the protocol to the international Framewor1 /onvention on

/limate /hange treaty, again with the obCective of reducing greenhouse gases in an effort

to prevent anthropogenic climate change.@*

• he 9estern /limate Initiative, to identify, evaluate, and implement collective and

cooperative ways to reduce greenhouse gases in the region, focusing on a mar1et-basedcap-and-trade system.A*

significantly profound challenge is to identify the natural environmental dynamics in contrast

to environmental changes not within natural variances. common solution is to adapt a static

view neglecting natural variances to e3ist. &ethodologically, this view could be defended whenloo1ing at processes which change slowly and short time series, while the problem arrives when

fast processes turns essential in the obCect of the study.

7/24/2019 scribd doc 1.docx

http://slidepdf.com/reader/full/scribd-doc-1docx 11/18

Climate

9orldwide climate classifications map

&ain article% /limate

/limate encompasses the statistics of  temperature, humidity, atmospheric pressure, wind,

rainfall, atmospheric particle count and numerous other meteorological elements in a givenregion over long periods of time.citation needed * /limate can be contrasted to weather , which is the

 present condition of these same elements over periods up to two wee1s.citation needed *

/limates can be classified according to the average and typical ranges of different variables,

most commonly temperature and precipitation. he most commonly used classification schemeis the one originally developed by 9ladimir Jppen. he hornthwaite system,B* in use since

B=A, incorporates evapotranspiration in addition to temperature and precipitation information

and is used in studying animal species diversity and potential impacts of climate changes.citation

needed *

Weather

;ainbows are optical and meteorological phenomenon that causes a spectrum of light to appear

in the s1y when the $un shines onto droplets of moisture in the Earths atmosphere.&ain article% 9eather 

9eather  is a set of all the phenomena occurring in a given atmospheric area at a given time.04* 

&ost weather phenomena occur in the troposphere,0*00* Cust below the stratosphere. 9eather

refers, generally, to day-to-day temperature and precipitation activity, whereas climate is the termfor the average atmospheric conditions over longer periods of time.06* 9hen used without

7ualification, "weather" is understood to be the weather of Earth.

7/24/2019 scribd doc 1.docx

http://slidepdf.com/reader/full/scribd-doc-1docx 12/18

9eather occurs due to density (temperature and moisture) differences between one place and

another. hese differences can occur due to the sun angle at any particular spot, which varies by

latitude from the tropics. he strong temperature contrast between polar and tropical air givesrise to the Cet stream. 9eather systems in the mid-latitudes, such as e3tratropical cyclones, are

caused by instabilities of the Cet stream flow. #ecause the Earths a3is is tilted relative to its

orbital plane, sunlight is incident at different angles at different times of the year. :n the Earthssurface, temperatures usually range K=4 L/ (44 LF to M=4 LF) annually. :ver thousands of

years, changes in the Earths orbit have affected the amount and distribution of solar energy

received by the Earth and influence long-term climate

$urface temperature differences in turn cause pressure differences. !igher altitudes are coolerthan lower altitudes due to differences in compressional heating. 9eather forecasting is the

application of science and technology to predict the state of the atmosphere for a future time and

a given location. he atmosphere is a chaotic system, and small changes to one part of the systemcan grow to have large effects on the system as a whole. !uman attempts to control the weather  

have occurred throughout human history, and there is evidence that civili'ed human activity such

as agriculture and industry has inadvertently modified weather patterns.

Li!e

here are many plant species on the planet.

7/24/2019 scribd doc 1.docx

http://slidepdf.com/reader/full/scribd-doc-1docx 13/18

n e3ample of the many animal species on the Earth.

&ain articles% ife, #iology and #iosphere

Evidence suggests that life on Earth has e3isted for about 6.@ billion years.0=* ll 1nown life

forms share fundamental molecular mechanisms, and based on these observations, theories on

the origin of life attempt to find a mechanism e3plaining the formation of a primordial single cell

organism from which all life originates. here are many different hypotheses regarding the paththat might have been ta1en from simple organic molecules via pre-cellular life to protocells and

metabolism.

lthough there is no universal agreement on the definition of life, scientists generally accept thatthe biological manifestation of life is characteri'ed by organi'ation, metabolism, growth,

adaptation, response to stimuli and reproduction.0>* ife may also be said to be simply the

characteristic state of organisms. In biology, the science of living organisms, "life" is the

condition which distinguishes active organisms from inorganic matter , including the capacity forgrowth, functional activity and the continual change preceding death.0?*0@*

diverse variety of living organisms (life forms) can be found in the biosphere on Earth, and

 properties common to these organisms  plants, animals, fungi,  protists, archaea, and bacteria  

are a carbon- and water -based cellular  form with comple3 organi'ation and heritable genetic information. iving organisms undergo metabolism, maintain homeostasis, possess a capacity to

grow, respond to stimuli, reproduce and, through natural selection, adapt to their environment insuccessive generations. &ore comple3 living organisms can communicate through variousmeans.

Ecosystems

7/24/2019 scribd doc 1.docx

http://slidepdf.com/reader/full/scribd-doc-1docx 14/18

;ainforests often have a great deal of biodiversity with many plant and animal species. his is

the 8ambia ;iver  in $enegals  Nio1olo-oba National <ar1 .&ain article% Ecosystem

n ecosystem (also called as environment) is a natural unit consisting of all plants, animals and

micro-organisms ( biotic factors) in an area functioning together with all of the non-living

 physical (abiotic) factors of the environment.0A*

/entral to the ecosystem concept is the idea that living organisms are continually engaged in a

highly interrelated set of relationships with every other element constituting the environment inwhich they e3ist. Eugene :dum, one of the founders of the science of  ecology, stated% "ny unitthat includes all of the organisms (ie% the "community") in a given area interacting with the

 physical environment so that a flow of energy leads to clearly defined trophic structure, biotic

diversity, and material cycles (i.e.% e3change of materials between living and nonliving parts)

within the system is an ecosystem."0B*

:ld-growth forest and a cree1  on arch &ountain, in the 2.$. state of :regon.

he human ecosystem concept is then grounded in the deconstruction of the humanOnature

dichotomy, and the emergent premise that all species are ecologically integrated with each other,as well as with the abiotic constituents of their   biotope.

greater number or variety of species or biological diversity of an ecosystem may contribute togreater resilience of an ecosystem, because there are more species present at a location to

respond to change and thus "absorb" or reduce its effects. his reduces the effect before theecosystems structure is fundamentally changed to a different state. his is not universally the

case and there is no proven relationship between the species diversity of an ecosystem and its

ability to provide goods and services on a sustainable level.

7/24/2019 scribd doc 1.docx

http://slidepdf.com/reader/full/scribd-doc-1docx 15/18

he term ecosystem can also pertain to human-made environments, such as human ecosystems 

and human-influenced ecosystems, and can describe any situation where there is relationship

 between living organisms and their environment. Fewer areas on the surface of the earth todaye3ist free from human contact, although some genuine wilderness areas continue to e3ist without

any forms of human intervention.

#iomes

&ap of errestrial biomes classified by vegetation.

&ain article% #iome

#iomes are terminologically similar to the concept of ecosystems, and are climatically andgeographically defined areas of ecologically similar climatic conditions on the Earth, such as

communities of plants, animals, and soil organisms, often referred to as ecosystems. #iomes are

defined on the basis of factors such as plant structures (such as trees, shrubs, and grasses), leaftypes (such as broadleaf and needleleaf), plant spacing (forest, woodland, savanna), and climate.

2nli1e eco'ones, biomes are not defined by genetic, ta3onomic, or historical similarities. #iomes

are often identified with particular patterns of  ecological succession and clima3 vegetation.

#iogeochemical cycles

/hloroplasts conduct photosynthesis and are found in plant cells and other eu1aryotic organisms.

hese are /hloroplasts visible in the cells of Plagiomnium affine  &any-fruited hyme-moss.

&ain article% #iogeochemical cycles

8lobal biogeochemical cycles are critical to life, most notably those of  water , o3ygen, carbon, 

nitrogen and phosphorus.64*

• he nitrogen cycle is the transformation of nitrogen and nitrogen-containing compounds

in nature. It is a cycle which includes gaseous components.

7/24/2019 scribd doc 1.docx

http://slidepdf.com/reader/full/scribd-doc-1docx 16/18

• he water cycle, is the continuous movement of water on, above, and below the surface

of the Earth. 9ater can change states among li7uid, vapour, and ice at various places in

the water cycle. lthough the balance of water on Earth remains fairly constant over time,individual water molecules can come and go.

• he carbon cycle is the biogeochemical cycle by which carbon is e3changed among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth.

• he o3ygen cycle is the movement of o3ygen within and between its three main

reservoirs% the atmosphere, the biosphere, and the lithosphere. he main driving factor ofthe o3ygen cycle is photosynthesis, which is responsible for the modern Earths

atmospheric composition and life.

• he phosphorus cycle is the movement of phosphorus through the lithosphere,

hydrosphere, and biosphere. he atmosphere does not play a significant role in the

movements of phosphorus, because phosphorus and phosphorus compounds are usually

solids at the typical ranges of temperature and pressure found on Earth.

Wilderness

 conifer forest in the $wiss lps ( National <ar1 ).

he h1lun &ountains and the ogia1 9ilderness within the ogia1 National 9ildlife ;efuge in

the 2.$. state of las1a.&ain article% 9ilderness

9ilderness is generally defined as a natural environment on Earth that has not been significantly

modified by human activity. he 9IG Foundation goes into more detail, defining wilderness

as% "he most intact, undisturbed wild natural areas left on our planet - those last truly wild

7/24/2019 scribd doc 1.docx

http://slidepdf.com/reader/full/scribd-doc-1docx 17/18

 places that humans do not control and have not developed with roads, pipelines or other

industrial infrastructure."6* 9ilderness areas and protected par1s are considered important for

the survival of certain species, ecological studies, conservation, solitude, and recreation.9ilderness is deeply valued for cultural, spiritual, moral, and aesthetic reasons. $ome nature

writers believe wilderness areas are vital for the human spirit and creativity.60*

he word, "wilderness", derives from the notion of wildness+ in other words that which is not

controllable by humans. he words etymology is from the :ld English wildeornes, which in turnderives from wildeor  meaning wild beast  (wild P deor Q beast, deer).66* From this point of view,

it is the wildness of a place that ma1es it a wilderness. he mere presence or activity of people

does not dis7ualify an area from being "wilderness." &any ecosystems that are, or have been,inhabited or influenced by activities of people may still be considered "wild." his way of

loo1ing at wilderness includes areas within which natural processes operate without very

noticeable human interference.

9ildlife includes all non-domesticated plants, animals and other organisms. Gomesticating wild

 plant and animal species for human benefit has occurred many times all over the planet, and hasa maCor impact on the environment, both positive and negative. 9ildlife can be found in all

ecosystems. Geserts, rain forests, plains, and other areasincluding the most developed urban sitesall have distinct forms of wildlife. 9hile the term in popular culture usually refers to

animals that are untouched by civili'ed human factors, most scientists agree that wildlife around

the world is (now) impacted by human activities.

view of wilderness in Estonia

Challenges

7/24/2019 scribd doc 1.docx

http://slidepdf.com/reader/full/scribd-doc-1docx 18/18

#efore flue-gas desulfuri'ation was installed, the air-polluting emissions from this power plant in

 New &e3ico contained e3cessive amounts of  sulfur dio3ide

ma'on ;ainforest in #ra'il. he tropical rainforests of $outh merica contain the largest

diversity of species on Earth, including some that have evolved within the past few hundred

thousand years.6=*6>*

$ee also% ist of environmental issues

It is the common understanding of natural environment  that underlies environmentalism  a

 broad political, social, and philosophical movement that advocates various actions and policies in

the interest of protecting what nature remains in the natural environment, or restoring ore3panding the role of nature in this environment. 9hile true wilderness is increasingly rare, wild  

nature (e.g., unmanaged forests, uncultivated grasslands, wildlife, wildflowers) can be found in

many locations previously inhabited by humans.

8oals commonly e3pressed by environmental scientists include%

• ;eduction and cleanup of pollution, with future goals of 'ero pollution+

• /leanly converting non-recyclable materials into energy through direct combustion or

after conversion into secondary fuels+

• ;educing societal consumption of  non-renewable fuels+

• Gevelopment of alternative, green, low-carbon or  renewable energy sources+

• /onservation and sustainable use of scarce resources such as water , land, and air+

• <rotection of representative or uni7ue or pristine ecosystems+

• <reservation of threatened and endangered species e3tinction+

• he establishment of nature and biosphere reserves under various types of protection+

and, most generally, the protection of biodiversity and ecosystems upon which all human

and other life on earth depends.